From owner-freebsd-current@FreeBSD.ORG Thu Nov 17 09:47:48 2011 Return-Path: Delivered-To: freebsd-current@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EF416106566C; Thu, 17 Nov 2011 09:47:48 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 846B18FC16; Thu, 17 Nov 2011 09:47:47 +0000 (UTC) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id LAA10726; Thu, 17 Nov 2011 11:47:45 +0200 (EET) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1RQyZM-000Bhv-Ru; Thu, 17 Nov 2011 11:47:45 +0200 Message-ID: <4EC4D83E.3090307@FreeBSD.org> Date: Thu, 17 Nov 2011 11:47:42 +0200 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:8.0) Gecko/20111108 Thunderbird/8.0 MIME-Version: 1.0 To: Kostik Belousov References: <20111113083215.GV50300@deviant.kiev.zoral.com.ua> <20111116202714.5ee4bd53@fabiankeil.de> <4EC43764.1020202@FreeBSD.org> <4EC4423A.3020904@FreeBSD.org> <20111117081533.GP50300@deviant.kiev.zoral.com.ua> <4EC4C712.8040701@FreeBSD.org> In-Reply-To: <4EC4C712.8040701@FreeBSD.org> X-Enigmail-Version: undefined Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Alexander Motin , freebsd-current@FreeBSD.org Subject: Re: Stop scheduler on panic X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 17 Nov 2011 09:47:49 -0000 on 17/11/2011 10:34 Andriy Gapon said the following: > on 17/11/2011 10:15 Kostik Belousov said the following: >> I have the following change for eons on my test boxes. Without it, >> I simply cannot get _any_ dump. >> >> diff --git a/sys/cam/cam_xpt.c b/sys/cam/cam_xpt.c >> index 10b89c7..a38e42f 100644 >> --- a/sys/cam/cam_xpt.c >> +++ b/sys/cam/cam_xpt.c >> @@ -4230,7 +4230,7 @@ xpt_done(union ccb *done_ccb) >> TAILQ_INSERT_TAIL(&cam_simq, sim, links); >> mtx_unlock(&cam_simq_lock); >> sim->flags |= CAM_SIM_ON_DONEQ; >> - if (first) >> + if (first && panicstr == NULL) >> swi_sched(cambio_ih, 0); >> } >> } > > I think that this (or similar) change should go into the patch and the tree. > And, BTW, I still would like to do something like the following (perhaps with td_oncpu = NOCPU and td_flags &= ~TDF_NEEDRESCHED also moved to the common code): Index: sys/kern/sched_ule.c =================================================================== --- sys/kern/sched_ule.c (revision 227608) +++ sys/kern/sched_ule.c (working copy) @@ -1790,7 +1790,6 @@ sched_switch(struct thread *td, struct thread *new td->td_oncpu = NOCPU; if (!(flags & SW_PREEMPT)) td->td_flags &= ~TDF_NEEDRESCHED; - td->td_owepreempt = 0; tdq->tdq_switchcnt++; /* * The lock pointer in an idle thread should never change. Reset it Index: sys/kern/kern_synch.c =================================================================== --- sys/kern/kern_synch.c (revision 227608) +++ sys/kern/kern_synch.c (working copy) @@ -406,6 +406,8 @@ mi_switch(int flags, struct thread *newtd) ("mi_switch: switch must be voluntary or involuntary")); KASSERT(newtd != curthread, ("mi_switch: preempting back to ourself")); + td->td_owepreempt = 0; + /* * Don't perform context switches from the debugger. */ Index: sys/kern/sched_4bsd.c =================================================================== --- sys/kern/sched_4bsd.c (revision 227608) +++ sys/kern/sched_4bsd.c (working copy) @@ -940,7 +940,6 @@ sched_switch(struct thread *td, struct thread *new td->td_lastcpu = td->td_oncpu; if (!(flags & SW_PREEMPT)) td->td_flags &= ~TDF_NEEDRESCHED; - td->td_owepreempt = 0; td->td_oncpu = NOCPU; /* Does anybody see any potential problems with such a change? -- Andriy Gapon